Thyroid disease Main Page
Editor-In-Chief: C. Michael Gibson, M.S., M.D. Associate Editor(s)-in-Chief: Seyedmahdi Pahlavani, M.D. 
The thyroid is one of the largest endocrine glands in the body. It has a regulatory effect on body metabolism by secreting hormones. The principal hormones b produced by the thyroid gland include thyroxine (T4) and triiodothyronine (T3). These hormones regulate the metabolism, growth and functioning of many other systems in the body. Iodine is an essential component of both T3 and T4. Any disturbance in the thyroid hormone production may result in various changes in body metabolism. Signs and symptoms of hypothyroidism are mostly related to the magnitude of the thyroid hormone deficiency and the course of the development of hormone deficiency manifesting as fatigue, cold intolerance, hypothermia, coarse skin, and weight gain. Whereas, hyperthyroidism may result in palpitations, insomnia, anxiety, weight loss, and heat intolerance. The most common cause of hypothyroidism is chronic autoimmune thyroiditis, (Hashimoto’s thyroiditis). However, it might be caused by other less common causes, such as secondary and even tertiary diseases. Hyperthyroidism can be due to hyperactivity of the thyroid gland itself (primary hyperthyroidism) or due to abnormalities in the pituitary gland or the hypothalamus causing irregularities in the pathways regulating the gland function. The most common cause of goiter is iodine deficiency and is more common in developing countries. Thyroid cancer refers to any of four kinds of tumors of the thyroid gland; papillary, follicular, medullary and anaplastic. Papillary and follicular tumors are the most common and are usually benign. Papillary and follicular tumors grow slowly, may recur, but are generally not fatal in patients under 45 years of age. Thyroiditis is a spectrum of conditions that may result in inflammation of the thyroid tissue. These disorders could be acute with a painful thyroid gland, such as subacute thyroiditis or infectious thyroiditis, or chronic and painless like painless thyroiditis, postpartum thyroiditis, or drug-induced thyroiditis. Thyroid nodule is defined as discrete lesions within the thyroid gland that is radiologically distinct from surrounding thyroid parenchyma. Thyroid nodule should always be evaluated in order to exclude the existence of a thyroid cancer. Thyroid nodule evaluation begins with the assessment of the thyroid hormone levels and involves search for any pathological findings on FNA.
Thyroid disorders could be classified as the nature of the disease and its symptoms.
For more information on Hypothyroidism, please click here.
For more information on Hyperthyroidism, please click here.
For more information on Goiter, please click here.
For more information on Thyroiditis, please click here.
For more information on Thyroid nodule, please click here.
For more information on Thyroid cancer, please click here.